In this article from the New York Times we find out what iPad users are downloading:

A quick spin through the charts of the best-selling applications available in iTunes illuminates the most popular selections.

Currently, the top three paid iPad applications belong to a suite of applications intended to give the iPad more heft as a machine for productivity. They are adaptations of Apple’s iWork tools and include Pages, a word processing application, Keynote, which allows users to create visually rich presentations, and Numbers, a spreadsheet application. Each sells for $9.99.

But perhaps the most interesting application on the top 10 list is one called Star Walk, a $2.99 astronomy application that morphs the iPad into a star chart. Pointing the tablet at the sky activates an internal digital compass, instantly locating stars, planets and other celestial bodies.  Tapping on an object reveals more information about it.

GoodReader, which costs 99 cents and is hovering in the fourth most downloaded slot, is a documents reader for the iPad that can handle a range of formats, including PDF files and high-resolution images. SketchBookPro, $8.99, a sophisticated drawing application that lets users craft paintings with their hands, is also on the list.

Games, of course, have been a big draw. Real Racing HD ($9.99), a driving game that transforms the iPad into a steering wheel, and Flight Control ($4.99), an air traffic simulator that includes a level in 3-D, are both on the top 10 list. Scrabble ($9.99) turns the iPad’s glossy screen into a vivid playing board where multiple players can use their iPhones as their letter trays and “flick” tiles down to the main board for game play.